Captain Lionel Messi has told Barcelona he wishes to leave the club immediately, a source confirmed on Tuesday, deepening the turmoil within the Catalan side less than two weeks after their humiliating 8-2 defeat by Bayern Munich.

The club source said Messi informed the club about his desire to leave by sending a burofax, a service used in Spain to urgently dispatch a document that requires proof to third parties.

A second source added that the burofax referred to a clause in the last contract the 33-year-old signed with the club which allowed him to leave for free, a clause that expired on June 10 this year.

Under the terms of the contract which expires in 2021, the only way Messi can leave without the club’s consent is if a rival side pays his release clause of 700 million euros ($828 million).

The second source said the player’s lawyers had informed the club that Messi wished to unilaterally rescind his contract in line with a clause in his contract.

“The club considers that the contract is fully binding until June 30, 2021,” added the second source.

The Argentine’s request to leave Barca comes a day after Spanish media reported that new coach Ronald Koeman told Messi’s close friend and strike partner, Luis Suarez, that he does not wish the Uruguayan to stay at the club.

“Koeman doesn’t want them,” wrote the Mundo Deportivo, picturing Suarez, midfielders Ivan Rakitic and Arturo Vidal and defender Samuel Umtiti.

Barca are in the midst of overhauling their squad following the trouncing by Bayern earlier this month, which condemned the club to a trophyless season for the first time in 12 years.

Messi, who has been named World Player of the Year a record six times, has grown increasingly unhappy in the last 12 months with how the club is being run.